The present invention relates in general to a method and apparatus for transferring digital information between electrical components and, in particular, to a method and apparatus for transferring digital information between electrical components without the use of a dedicated data clock or data over sampling.
Presently, it is known for two or more electronic devices to exchange information or data using a serial data stream. Known methods of data transfer include a serial peripheral interface (SPI) that uses a dedicated data clock, data and enable signals to transfer serial data. Such interfaces are typically used in applications requiring data to be transferred from one electronic device or component to another electronic device or component.
One particular application in which data is transferred between electrical components is found in integrated circuit architectures used in wireless products that have a radio frequency integrated circuit (RF IC) and a baseband integrated circuit (BB IC). The RF IC receives and downconverts RF signals to baseband data signals that are coupled to the BB IC for further processing. The BB IC, among its various functions, may process the baseband data signals to develop a digital error or frequency control signal that is coupled to the RF IC. The RF IC may use the frequency control signal to correct and control its receive frequency synchronization. Additionally, the BB IC may generate a digital audio signal that may represent audio, such as voice, which is coupled to the RF IC for subsequent broadcast.
The use of an SPI to transfer the baseband data signals, the digital frequency control signal and the digital audio signal between the RF IC and the BB IC may require as many as nine dedicated pins on the integrated circuit chip (three pins for each signal to be transferred) and, therefore, may add cost and complexity to both the RF IC and the BB IC.